The goal of the proposed work is a system that simulates the auditory-perceptual effects of hearing loss in combination with hearing aids, cochlear implants, or other auditory prostheses. This simulator will be completely wearable for use in everyday settings without occupying hands or eyes. It will be computer-programmable to allow for extensive changes of system characteristics. It will be a binaural system, with loss and prosthesis characteristics independently specifiable for the left and right channels, and it will provide simple controls so that the user can switch among several loss and prosthesis settings. The eventual goal is to make the simulator available at moderate cost (approximately $700) for the following applications: training audiologists and educators of the deaf; demonstrations in hearing-conservation and public education programs; demonstrations for families of hearing-impaired and deaf persons; demonstrations for prospective hearing aid users; and as a research tool. The work in Phase I developed the core DSP technology for the system and demonstrated the feasibility of a hybrid threshold shift method that uses passive attenuation, masking noise, and automatic gain control to enable accurate simulation of hearing losses as large as 100 dB for a user immersed in a sound field. Proposed work in Phase II will refine the hardware and signal-processing components of the system, improve ergonomic aspects of the system, develop a user interface, and deliver prototype systems for field evaluations by collaborators involved in professional training, aural rehabilitation/counseling, and hearing conservation.